Enhanced cooling design for computing device

ABSTRACT

Enhanced cooling for electronic components within a computing device is provided. Blowers are preferably leveraged as air movers, and an airflow deflection surface (preferably configured as a ramp) is disposed within a plenum to guide airflow under an electronic component (such as a hard disk drive or solid state drive), the electronic component being placed in an inverted alignment whereby a surface having a higher heat transfer rate is facing down (toward the blower), and then into an intake of the blower. Air output from the blower may then pass into a downstream plenum formed at least in part by the blower, an inverted downstream electronic component, and a support member thereof, thus providing serial cooling of the downstream component. Anti-recirculation flaps are preferably disposed at the air output of the blower.

BACKGROUND OF THE INVENTION

The present invention relates to enhanced cooling for electroniccomponents within a computing device, and deals more particularly withproviding increased cooling while leveraging blowers as air movers.

Physical space inside a computing device such as a server is limited,and it is desirable to use this space efficiently and effectively. It isdesirable to accommodate as many hard disk drives or solid state driveswithin a computing device as technically feasible, for example, toprovide optimum storage from the computing device. (Hard disk drives arealso referred to herein as hard drives or disk drives, or simply asdrives. References to such drives should be interpreted as includingsolid state drives.) More disk drives operating mean more heatgenerated, however, and sufficient cooling must be provided so that thedrives (and other components) do not overheat.

BRIEF SUMMARY OF THE INVENTION

The present invention provides for enhanced cooling of components insidea computing device. In one embodiment, an enhanced cooling solutionpreferably comprises: an air mover having an intake and an exit; atleast one electronic component, the electronic component placed in aninverted alignment whereby a surface thereof having a higher heattransfer rate is facing downward toward the air mover; an airflowdeflection surface disposed in a plenum, the plenum being disposedbetween the air mover and the surface of the electronic component; andthe airflow deflection surface and the intake causing an airflow paththat cools the surface of the electronic component to pass, at least inpart, between the downward-facing surface of the electronic componentand an upper side of the airflow deflection surface before entering intothe intake of the air mover, the upper side of the airflow deflectionsurface being disposed toward the downward-facing surface of theelectronic component. The cooling system may further comprise: at leastone downstream electronic component, the downstream electronic componentplaced in the inverted alignment whereby the surface thereof having thehigher heat transfer rate is facing downward toward the exit of the airmover; a downstream plenum, the downstream plenum formed at least inpart by the downward-facing surface of the downstream electroniccomponent, the air mover, and a support member supporting the downstreamelectronic component, the downstream plenum receiving airflow from theexit of the air mover and causing the airflow path to cool the surfaceof the downstream electronic component by passing, at least in part,beneath the downward-facing surface of the downstream electroniccomponent before exiting from the downstream plenum. The support memberis preferably configured with a plurality of perforations, theperforations providing airflow impedance to pressurize the downstreamplenum while allowing the airflow to exit the downstream plenum. The airmover is preferably a blower. In another embodiment, a method forenhanced cooling of electronic components within a computing device isprovided, comprising: disposing an air mover within a housing of thecomputing device, the air mover having an intake and an exit; placing atleast one electronic component in an inverted alignment along a front ofthe housing, the inverted alignment causing a surface of the electroniccomponent having a higher heat transfer rate to face downward toward theair mover; and disposing an airflow deflection surface in a plenumwithin the housing, the plenum being disposed between the air mover andthe surface of the electronic component, whereby the airflow deflectionsurface and the intake cause an airflow path that cools the surface ofthe electronic component to pass, at least in part, between thedownward-facing surface of the electronic component and an upper side ofthe airflow deflection surface before entering into the intake of theair mover, the upper side of the airflow deflection surface beingdisposed toward the downward-facing surface of the electronic component.

These and other aspects of the present invention may be provided in oneor more embodiments. It should be noted that the foregoing is a summaryand thus contains, by necessity, simplifications, generalizations, andomissions of detail; consequently, those skilled in the art willappreciate that the summary is illustrative only and is not intended tobe in any way limiting. Other aspects, inventive features, andadvantages of the present invention, as defined by the appended claims,will become apparent in the non-limiting detailed description set forthbelow.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention will be described with reference to the followingdrawings, in which like reference numbers denote the same elementthroughout.

FIG. 1 illustrates an example configuration for placement of drives andan air mover, according to an embodiment of the present invention;

FIG. 2 provides an illustration of hard drives arranged in a two-levelconfiguration, where a second level is downstream of a first level, andFIG. 3 provides another view of the system, showing how the presence offirst-level hard drives may look from an end of the computing device;

FIG. 4 depicts a top view of the computing device, illustrating aside-to-side plenum;

FIG. 5 illustrates a side view of an example configuration, illustratinguse of a perforated segment as a type of outer wall alongside an outeredge of a blower, and FIG. 6 illustrates an alternative version of suchperforated segment; and

FIG. 7 illustrates an alternative configuration of an airflow deflectionsurface.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention are directed toward enhancedcooling for electronic components within a computing device. Anembodiment provides increased cooling while leveraging blowers as airmovers. As noted earlier, it is desirable to accommodate as many diskdrives within a computing device as technically feasible. It is alsodesirable to have as many hard drives accessible from the front of thesystem as possible. Having the system's air moving devices, such as fansor blowers, at the front of the system is often the best solution ofproviding airflow into the system. An embodiment of the presentinvention is configured to house air movers for the computing devicewithin the same physical space that some prior art devices used for onlythe disk drives. (For ease of reference, the term “server” is usedherein to refer to the computing device, although this is by way ofillustration and not of limitation.) Prior art approaches to coolingcomponents within a server used counter-rotating fans, and thevolumetric space for those fans was typically internal to theserver—either occupying space above the mother board or sandwichedbetween the top and bottom of the chassis. With increased placement ofmemory or other components within the server, however, it is no longerfeasible to use counter-rotating fans (e.g., because space previouslyused for the fans is either reduced or is simply no longer available, orbecause placing the fans in alternative locations would result inphysical constraints on the air intake that would lead to inadequatecooling).

An embodiment of the present invention provides enhanced cooling forhard drives that are now rotated flat 90 degrees (as compared to a priorart configuration) and located above the air movers, rather than a priorart approach of using hanging hard drives located upstream from airmovers, or downstream therefrom if the bank(s) of hard drives areinternal to the system or at the rear of the system. Prior artapproaches using blowers conventionally draw airflow from one plane andexhaust it out at a 90 degree angle, and do not place drives above airmovers because it is difficult to get airflow directed to where it needsto be. Accordingly, using blowers in a conventional configuration wouldresult in insufficient airflow. An embodiment of the present inventioninverts the hard drives, placing them into a configuration that mostobservers would consider to be “upside down”. This is intentional,however, because there is better cooling on one side of a hard drive inthe configuration used by an embodiment of the present invention, whichplaces this side as close to the airflow path as is feasible.

FIG. 1 illustrates an example configuration for placement of drives andan air mover, according to an embodiment of the present invention, wherethis configuration depicts two inverted hard drives 100 a, 100 b and ablower 130. Note that an embodiment of the present invention may includeany number of internal inverted hard drives that can fit into thesystem. A first of the two hard drives 100 a is placed over the blower130, and a second of the hard drives 100 b is placed downstream from thefirst hard drive 100 a. Downstream in this connotation means that thefirst hard drive 100 a is typically placed, along with other similarhard drives, along a front edge of the server. Hard drive 100 b islocated behind—i.e., downstream of—hard drive 100 a in terms of physicalplacement and airflow.

Notably, the hotter side of a hard drive 100 a, 100 b is not placed asthe topmost side, even though heat rises, because the rate of airflowwhen using an embodiment of the present invention far outweighs the rateof heat rising. Accordingly, an embodiment of the present inventionplaces the side of the drive that has the higher heat transfer rate asfacing down, toward the air mover, thereby exposing the surface of thedrive to the highest airflow velocity. Therefore, it is not necessary topull air around the surfaces of the drives (although some air can leakaround all sides, flushing the heated airflow away from the harddrives), which instead are primarily cooled by airflow directed towardone side thereof when using an embodiment of the present invention.

FIG. 1 also illustrates placement of an airflow deflection surface 110between the under side of the first hard drive 100 a and the blower 130.This airflow deflection surface 110 is angled upward within the plenumshown generally at 140 (i.e., within the air space existing between thelower surface of hard drive 100 a and the upper surface of blower 130).Airflow deflection surface 110 is also referred to herein as a ramp, forease of reference. The airflow deflection surface may be comprised ofone or more angled ramp pieces. (See FIG. 5, for example, illustrating aplurality of ramps 110.) Alternatively, the ramp may be one piece at asimilar angle, but this may lead to suboptimal results. Airflow entersthe configuration illustrated in FIG. 1 generally from the left-handside; see the arrows denoted by reference numbers 120 a, 120 b. Arrow120 b corresponds generally to an airflow path where room air directlyenters the blower 130 through an intake area 130 a, as in a prior artapproach. Preferably, a perforated surface is present alongside an outeredge of blower 130 (and perforations may also extend upward for anentirety of this edge of the housing, and this is discussed below withreference to FIGS. 5 and 6), allowing room air to enter while preventingentry of objects into the housing of the system. Air entering accordingto arrow 120 b is generally drawn into the system by low pressurecreated at the blower intake area 130 a. Arrow 120 a corresponds to anairflow path where air enters the plenum 140 and is forced upward by theangle of the ramp 110. Once the air reaches the far end of the ramp 110,arrow 120 a shows that the path of the airflow then turns downward,entering intake area 130 a of the blower 130.

Notably, ramp 110 entices the airflow into the system as far as feasiblypossible, keeping the cooling airflow up against the surface of the harddrive until that air reaches the end of the ramp; without this ramp 110,air would come into the system as shown by arrow 120 b and would godirectly into blower intake area 130 a, bypassing the surface of thehard drive 100 a. Preferably, the angle of ramp 110 is adapted so as tokeep the ramp as far above the blower intake area 130 a as technicallyfeasible, to thereby maximize the cooling path of the airflow along thesurface of hard drive 110 a as well as to maximize airflow intake of theblower. The placement and length of ramp 110 determine how far theairflow will travel along the surface of hard drive 110 a. The dimensionbetween the lower surface of hard drive 110 a and the highest end oframp 110 serves to balance the amount of airflow above and below theramp. Ramp 110 may be constructed of generally any solid material thatdoes not induce airflow drag, including steel, a rubber membrane, orfoam, as several examples of non-limiting choices.

Once air enters blower 130, it is pushed out into the rest of thesystem. In the configuration shown in FIG. 1, this corresponds generallyto air exiting blower 130 from a blower exit area 130 b (shown on theright-hand side of blower 130) into another plenum 160; see the arrowsdenoted by reference numbers 120 c, 120 d. Blower 130 is preferablyconfigured with a plurality of anti-recirculation flaps 150 on thisblower exit area 130 c. These flaps aim to prevent airflow that exitsblower 130 from flowing in the opposite direction back through theblower in the event of a blower failure. In addition, flaps 150 may aidin equalizing airflow distribution within the plenum 160. Each blowerused in the system may have the same, or a different, number of flaps.The example configuration in FIG. 1 depicts use of three flaps at 150,by way of illustration but not of limitation. Flaps 150 are preferablyconstructed of a lightweight, yet stiff, material. Examples of materialthat may be used for flaps 150 include polycarbonate or plastic. Plenum160 is generally bounded at the top by downstream hard drive 100 b andbounded at the sides by blower 130 and a support member 170 thatsupports hard drive 100 b. Support member 170 is preferably a perforatedwall, where the perforations provide sufficient airflow impedance tocreate a pressurized plenum 160 that better distributes airflow forcooling the system and also knocks down (i.e., reduces) the localizedhigh-velocity airflow exiting from blower 130. Accordingly, arrow 120 ccorresponds generally to an airflow path where air within plenum 160blows upward, against the surface of downstream hard drive 100 b. Arrow120 d, on the other hand, corresponds to an airflow path where airwithin plenum 160 escapes through perforations of support member 170. Aconfiguration as illustrated in FIG. 1 minimizes pressure drop withinthe system while maximizing air velocity along the hard drives andoptimizes the balance of airflow in the system, which in turn maximizescooling. When using techniques disclosed herein, including themulti-angled ducting provided by airflow deflection surface 110 andserial cooling provided by the airflow path, the downstream componentsare cooled with generally the same efficiency (i.e., cooled to generallyan equal temperature) as the upstream components.

Note that the number of successive hard drive levels is shown in FIG. 1as two by way of illustration but not of limitation: a configurationusing a single level of hard drive or a configuration using more thantwo successive levels of hard drives is also within the scope of thepresent invention. FIG. 2 provides an illustration of hard drivesarranged in a two-level configuration, having six hard drives in thefirst level and two in the second level. (Placement of two hard drivesin the second level is by way of illustration and not of limitation.)Reference numbers 100 a of the first level correspond to 100 a of FIG.1, and reference numbers 100 b of the second level correspond to 100 bof FIG. 1. Generally, a configuration may support as many successivehard drive levels as will fit within the system housing, and the airflowbalancing plenum is preferably designed for that possibility. Inaddition, it should be noted that while discussions herein referprimarily to inverted disk drives, an embodiment of the presentinvention may also be used with other types of components. By way ofexample, an inverted hard drive form factor might be used to hold aredundant array of independent Solid State Drives (SSDs), an electroniccomponent card, or a micro-tape drive.

FIG. 3 provides another view of the system, showing how the presence offirst-level hard drives 100 a may look from an end of the computingdevice.

FIG. 4 depicts a top view of the computing device, where first-levelhard drives 100 a are covered, in this illustration, by a structuralmember of some type; see reference number 400. Arrow 410 points to adashed rectangle (provided for illustration only) that generallycorresponds to the plenum 160. Accordingly, it can be seen that plenum160 generally encompasses the entire side-to-side width of the computingdevice. In this example configuration, two downstream hard drives 100 beach have an underlying support member 170 (not visible in FIG. 4; seesupport member 170 of FIG. 1), and this support member may optionallyextend the entire side-to-side width. Also in this exampleconfiguration, a rectangular bulkhead 420 is depicted, and drives 100 bare shown (by way of illustration only) as being inserted through thisbulkhead 420.

FIG. 5 illustrates a side view of an example configuration, wherereference number 130 corresponds to blower 130 of FIG. 1, referencenumber 100 a corresponds to hard drive 100 a of FIG. 1, and referencenumber 110 corresponds to ramp 110 of FIG. 1. FIG. 5 illustrates use ofa perforated surface as a type of outer wall alongside an outer edge ofblower 130, denoted in FIG. 5 using reference number 500. A perforatedsegment 510 is also depicted, where this perforated segment 510 forms atype of outer wall that extends generally from a level of the top of theblower 130 to a level of the bottom of hard drive 100 a. In the depictedexample, perforated segment 510 is shown as a hollow chamber havingperforations on both the interior wall 511 and exterior wall 512. Theseperforations in segment 510 allow room air to enter plenum 140 withoutbeing overly impeded. An alternative version 610 of perforated segment510 is shown in FIG. 6, where the interior wall 611 of perforatedsegment 610 has fewer perforations as compared to the interior wall 511(and exterior wall 612 is the same as exterior wall 512). Notably, theperforations in interior wall 611 are now clustered in an upper portionthereof. Accordingly, airflow can only enter into plenum 140 from anupper height that corresponds to the upper portion of wall 611. Thisapproach forces the airflow to be closer to the hard drive 100 a surfacethat is to be cooled, while still being forced downward into the blowerby ramp 110. Note that the size of the perforations in interior wall 611may be the same as, or different from, the size of the perforations inexterior wall 612. For example, the perforations in interior wall 611may be larger in size than those in exterior wall 612. Note that in analternative embodiment, the interior wall 511 or 611 may be removedentirely if not needed for structural integrity requirements of thisportion of the system.

As contrasted to prior art cooling approaches which rely on fans,blowers used in an embodiment of the present invention add impedance andpressure loss (while not significantly impacting overall airflow rate).As will be understood, a computing device such as a server typicallycontains numerous components, and use of the enhanced cooling systemdescribed herein is believed to deliver better cooling throughout thehousing of the system. Blowers also generally have a lower acousticalsignature than fans, which will tend to reduce the audio acoustic noiseof the computing device, due in large part to the ability to takeadvantage of a blower producing more pressure and therefore needinglower airflow through a well-ducted system as compared to the amount ofairflow required when using fans with less airflow channeling andducting.

Ramps as described herein also block some line-of-sight viewing, throughperforated segment 510 or perforated segment 610, to the blower intakearea 130 a of blower 130. This also provides an acoustical benefit(although on the order of only several decibels). Additional acousticalabsorbing material may be added to the ramp, if desired, to furtherdampen sound that may be coming, for example, from the blower or airintake. Ramps as described herein also serve as a finger guard in a casewhere someone might remove a first-level hard drive 100 a: the rampmakes it unlikely that the person could reach in far enough to contactthe blower intake area 130 a, thus providing a measure of safety.Anti-recirculation flaps 150 also generally prevent a person frompushing their fingers into the blower exit area 130 b of blower 130.Thus, no additional finger guards are required on the individual blowerunit. Omitting the requirement of finger guards also slightly increasesthe efficiency of the blower device and reduces some acoustic penalties.

FIG. 7 illustrates an alternative configuration for the airflowdeflection surface, or ramp. In this alternative, shown at referencenumber 710, the ramp has a greater number of segments as compared toramp 110. FIG. 7 also illustrates that the segments of ramp 710 may beplaced at multiple angles.

As can be seen from the above discussions, an embodiment of the presentinvention enhances cooling of components in a computing device. Whilediscussions herein are primarily in terms of enhancing cooling within aserver device, this is by way of illustration and not of limitation:cooling techniques disclosed herein may be used with other types ofdevices without deviating from the scope of the present invention.

While embodiments of the present invention have been described,additional variations and modifications in those embodiments may occurto those skilled in the art once they learn of the basic inventiveconcepts. Therefore, it is intended that the appended claims shall beconstrued to include the described embodiments and all such variationsand modifications as fall within the spirit and scope of the invention.It is also to be noted that while aspects of the present invention arereferred to herein with regard to “an embodiment” of the presentinvention, this should not be construed as requiring each aspect to bepresent in a single embodiment.

The invention claimed is:
 1. A cooling system for electronic componentswithin a computing device, comprising: an air mover having an intake andan exit; an electronic component placed in an inverted alignment wherebya surface thereof having a higher heat transfer rate is facing downwardtoward the air mover; an airflow deflection surface disposed in aplenum, the plenum being disposed between the air mover and the surfaceof the electronic component; the airflow deflection surface and theintake causing an airflow path that cools the surface of the electroniccomponent to pass, at least in part, between the downward-facing surfaceof the electronic component and an upper side of the airflow deflectionsurface before entering into the intake of the air mover, the upper sideof the airflow deflection surface being disposed toward thedownward-facing surface of the electronic component; a downstreamelectronic component, the downstream electronic component placed in theinverted alignment whereby the surface thereof having the higher heattransfer rate is facing downward toward the exit of the air mover; and adownstream plenum, the downstream plenum formed at least in part by thedownward-facing surface of the downstream electronic component, the airmover, and a support member supporting the downstream electroniccomponent, the downstream plenum receiving airflow from the exit of theair mover and causing the airflow path to cool the surface of thedownstream electronic component by passing, at least in part, beneaththe downward-facing surface of the downstream electronic componentbefore exiting from the downstream plenum.
 2. The cooling systemaccording to claim 1, wherein the support member is configured with aplurality of perforations, the perforations providing airflow impedanceto pressurize the downstream plenum while allowing the airflow to exitthe downstream plenum.
 3. The cooling system according to claim 2,wherein the perforations further reduce a velocity of airflow exitingfrom the exit of the air mover.
 4. The cooling system according to claim1, wherein the air mover is a blower.
 5. The cooling system according toclaim 1, wherein the electronic component is a hard disk drive.
 6. Thecooling system according to claim 1, wherein the electronic component isa solid state drive.
 7. The cooling system according to claim 1, whereinthe airflow deflection surface is configured as an angled ramp.
 8. Thecooling system according to claim 1, wherein air enters the coolingsystem through a perforated surface disposed as an outer wall of ahousing of the computing device, the perforated surface comprising aplurality of perforations that allow the air to enter the cooling systemwithout being overly impeded.
 9. The cooling system according to claim1, wherein air enters the cooling system through a hollow chamberdisposed as an outer wall of a housing of the computing device, thehollow chamber comprising a outer chamber wall and an inner chamberwall, the outer chamber wall comprising a first plurality ofperforations that allow the air to enter the chamber and the innerchamber wall comprising a second plurality of perforations that allowthe air to enter the cooling system without being overly impeded, thesecond plurality of perforations being fewer in number than the firstplurality.
 10. The cooling system according to claim 9, wherein thesecond plurality of perforations are clustered in an upper portion ofthe inner chamber wall to cause the airflow to enter into the plenumfrom an upper height so as to be in close proximity to thedownward-facing surface of the electronic component before being forceddownward into the air mover by the airflow deflection surface.
 11. Amethod for cooling electronic components within a computing device,comprising: disposing an air mover within a housing of the computingdevice, the air mover having an intake and an exit; placing anelectronic component in an inverted alignment along a front of thehousing, the inverted alignment causing a surface of the electroniccomponent having a higher heat transfer rate to face downward toward theair mover; disposing an airflow deflection surface in a plenum withinthe housing, the plenum being disposed between the air mover and thesurface of the electronic component, whereby the airflow deflectionsurface and the intake cause an airflow path that cools the surface ofthe electronic component to pass, at least in part, between thedownward-facing surface of the electronic component and an upper side ofthe airflow deflection surface before entering into the intake of theair mover, the upper side of the airflow deflection surface beingdisposed toward the downward-facing surface of the electronic component;placing an additional electronic component downstream of the electroniccomponent, the downstream electronic component placed in the invertedalignment whereby the surface thereof having the higher heat transferrate is facing downward toward the exit of the air mover; and disposinga downstream plenum in the housing, the downstream plenum formed atleast in part by the downward-facing surface of the downstreamelectronic component, the air mover, and a support member supporting thedownstream electronic component, the downstream plenum receiving airflowfrom the exit of the air mover and causing the airflow path to cool thesurface of the downstream electronic component by passing, at least inpart, beneath the downward-facing surface of the downstream electroniccomponent before exiting from the downstream plenum, wherein the supportmember is configured with a plurality of perforations, the perforationsproviding airflow impedance to pressurize the downstream plenum whileallowing the airflow to exit the downstream plenum, wherein theperforations further reduce a velocity of airflow exiting from the exitof the air mover.
 12. The method according to claim 11, wherein the airmover is a blower.
 13. The method according to claim 11, wherein theelectronic component is selected from the group consisting of a harddisk drive, a redundant array of independent Solid State Drives (SSDs),an electronic component card, or a micro-tape drive in a form factor ofa hard disk drive.
 14. The method according to claim 11, wherein theelectronic component is a solid state drive.
 15. The method according toclaim 11, wherein the airflow deflection surface is configured as anangled ramp.
 16. The method according to claim 11, wherein air entersthe cooling system through a perforated surface disposed as an outerwall of a housing of the computing device, the perforated surfacecomprising a plurality of perforations that allow the air to enter thecooling system without being overly impeded.
 17. The method according toclaim 11, wherein air enters the cooling system through a hollow chamberdisposed as an outer wall of a housing of the computing device, thehollow chamber comprising a outer chamber wall and an inner chamberwall, the outer chamber wall comprising a first plurality ofperforations that allow the air to enter the chamber and the innerchamber wall comprising a second plurality of perforations that allowthe air to enter the cooling system without being overly impeded, thesecond plurality of perforations being fewer in number than the firstplurality.
 18. The method according to claim 17, wherein the secondplurality of perforations are clustered in an upper portion of the innerchamber wall to cause the airflow to enter into the plenum from an upperheight so as to be in close proximity to the downward-facing surface ofthe electronic component before being forced downward into the air moverby the airflow deflection surface.